Screw device



Aug. 13, 1929. v L. HORN I 1,724,590

SCREW DEVICE Filedpct. 21, 192'? 2 sheets sheefl 1 Aug. 13, 1929. v HORN 1,724,590

- SCREW DEVICE i A Filed Oct. 21, 1927 2 Sheets-Sheet" 2 J/ jawenzap Patented Aug. 13, 1929.

nnrraa. sraras LEONHARD HORN, OF WURZBURG, GERMANY.

scanw DEVICE.

Application filed October 21, 1927, Serial No. 227,846, and in Switzerland and Germany October 27, 1926.

This invention relates to a screw-device designed to move first rapidly an element constructed like a nut'and designed to be clamped or to be brought into a stationary position by rotation of a screw-spindle, the rapid moving in first instance being effected by means of a steep pitched thread, an automatically locking thread entering then into function for clamping.- Hitherto it has been necessary, in order to adjust 'the elements to be clamped, to rotate the screw-spindle several times, as for the clamping a flat automatically acting thread is required. This unnecessary work of rotating the spindle has to be avoided according to the invention.

The invention can be used in the mechanisms and in machine-building in general for adjusting an element, for clan'iping an article, for locking a device, or for carrying out a static pressure at stamping, punching and the like. i

The invention is illustrated, byway of example, in the accompanying drawing which shows in the Figs. 1 to 6 several examples of application of the invention. Fig. 1 shows in section a screw-device which generally illustrates the operation.

Fig. 2 is a sectional elevation of a valve to which the invention is applied.

Fig. 3 is a view showing the invention as applied for operating the slide valve (not shown) of a steam engine.

Fig. 4 is a sectional view similar to Fig. 1 showing an adjustable feature. Figs. 5 and 6 are sectional views showing the, application of the invention for clamping printing plates on the cylinder (if a printing machine.

In this device a claw 1 has to be shifted a distance a: by means of a screw-spindle 2, so that this claw is pressed in the one extreme position againstan abutment 3 and in the other extreme position against an abut-' ment 4. The spindle 2 has two threadedportions, a steep-pitched thread 5 and a fiat automatically braking thread 6. The two threaded portions; have oppositely directed pitch. The steep thread 5 co-operates with the stationary abutment 4 which has a corresponding internal thread 7 indicated by broken lines. The automatically braking thread 6 engages with an internal thread of claw 1. The left end 8'of the spindle 2 is mounted shiftably and rotatably in the abutment 3/ A", square 9 ison the right end of the spindle? Suppose the steep pitch thread 5 be at the right of the abutment 4 so that it can engage with the inner thread 7, and the claw 1 be pressed against the inner side of this abutment 4. lVhen in this position of the steep thread 5 the spindle 2 isturned to the rightwith the aid of the square 9, the steep thread 5 is screwed into the female thread and through the abutment 4 and the claw 1 is very rapidly moved towards the left .abutment 3. When the steep thread 5 has come out of the abutment 4, the claw 1 stands at a short distance from the abut- I ment When the spindle isfurther turned in the same direction, the steep thread 5 bears against the lnner side of the abutment 4, and the automatically braking thread '6 rotates in the corresponding female thread,

whereby theclaw 1 is slowly pressed against. the abutment 3. This position of claw 1 is shown in the drawing.

lVhcn, in the position of the claw shown,

the spindle is turned in opposite direction as before, i. e. to the left, the steep thread 5 bears at first still against the abutment 4 and the thread 6 turns consequently in the claw and pulls the same slowly to the right until as it can engage with the internal thread 7.

From this moment the steep thread 5 screws through the abutment 4 until it is again at the right-hand-side of the latter. The

. spindle is then locked again and the thread 6 rotates in the claw 1, which is consequently pressed against the abutment 4..

' In Fig. 2 a valve is shown which has to be moved very rapidly and the valve-disk- 11 of which has to be pressed with a certain force upon the valve-seat 12. The operation for moving the valve is similar to that of the device shown in Fig. 1 and the corresponding parts are designated by the same The stroke of the valve reference numerals.- sjllmlted by the valve ll'striking against the lower surface of the valve-casing 14.

A difference between this form of construction and that shown in'Fig. 1 consists in that the spindle 2 has only the steep thread 5 and that the automatically locking thread 6 is arranged on the valve shaft 15* and engages with the hollow spindle 2. The

valve-shaft is prevented from rotating by a transverse part 16. In Fig. 3 an arrangement is illustrated by .means ofwhich a slide-valve (not shown) 'of a steam-engine has to be rapidly shifted by means of an elbow-lever 17 and of a connecting rod 18 and to' be locked in both extreme positions by the automatically brak ing thread 6. The connecting rod 18 is hingedlymounted on the movable nut 1.-

. The operation is similar to that of the device adjustable the distance along which the element 1 to be locked (Fig. l) is moved by the automatically braking thread 6. Ac-

cording to the invention this is made possible by arranging rotatably in a stationary element the element 4 which has the internal thread 7 for the steep pitched thread 5. Such an arrangement is shown in Fig. 4. The stationary part, in which the element 4 having internal thread is rotatably mounted, is designated by 19. The rotatable element 4.- has a flange 20 in which, as indicated by broken lines,- arc-shaped slots 21 are provided. Through these slots screw-bolts 22 extend by means of which the element 4, after it has been adjusted as desired, can be securely fixed in its position. According to the adjusting of element 4 the steep pitched thread 5 bears sooner or later against the outer surfaces of the, element 4, and the automatically locking thread comes into operation atthe rotation of the spindle 2 accordingly on a longer-or shorter distance.

The new screw-device is specially adapted for clamping printing plates on the cylinders of printing machines. In Figs. 5 and 6 a portion of such a cylinder is shown, a

plate 25 being securely clamped in position and another plate being liberated. The cylinder 26 -is carried b a shaft 27. The toothed crown 28 of t e. e linder 26 rests on two disks 29 and 30. nto the disk 29 wvhich is connected with the cylinder26 by screw-bolts 31, an element 32 is inserted which has the female-thread for the steeppitched thread 5 of the spindle 2; The inner end of the spindle 2 is journalled in a bore 33 of the cylinder 26. A portion 34 of spindle'2 is of square cross-section to facilitate rotating of the spindle. On the adjustable element 1, which has the automatically braking thread 6, a gripper 35 is arranged which bears against the bevelled .edge of plate 25 and clamps the, same when it is in the position shown in Fig. 5. The operation of the screw-device is the same as above described.

I claim 1. A screwdevice for adjusting an element, comprising in combination a spindle having a threaded portion with steep-pitch and an automatically locking threaded portion of oppositely directed pitch, a pair of spaced .abutments in which said spindle is rotatably and axially movable, one of said abutments having a female-thread with which engages said steep-threaded portion of said shiftable and rotatable spindle, and an'adjustable element movable between the abutments and having a threaded portion engaged by said automatically locking thread of the spindle,- said threaded abutment being of such length that the steeppitched thread after having been screwed out of said abutment bears against said abutment 'so' that said automatically locking thread begins to act for a feed motion on the adjustable element. 2-. A screw-device for-adjusting an element, comprising in combination a spindle having a threaded portion with steep-pitch and an automatically locking threaded portion of oppositely directed pitch, an abutment in which the spindle isslidably and ing a female-thread with which engages said steep-threaded portion of saidspindle, an adjustable element movable between the of sucha length so that the steep-pitched thread after having been screwed out of said abutment bears against said abutment so that said automatically locking thread begins to act for a feed motion upon the adjustable element.

3. A screw-device as specified in claim 1, in which the abutment for the'stcep thread is of such length and arranged in such a manner that the steep thread can' be unscrewed from said abutment in both directions and bear against the. same from each side so that the nut of the automatically that it can be secured in its adjusted position.

In testimony whereof I aflix my signature.

LEONHARD HORN.

' rotatably mounted, a second abutment hav- 

